(0338) Xerostomia Following Radiotherapy for Head and Neck Cancer: A Real-World National Analysis

Introduction: Xerostomia is a known complication of radiotherapy (RT) for head and neck cancers (HNC). The incidence and clinical factors which contribute to its development remain under investigation. Here, we use a real-world database to further elucidate factors associated with xerostomia development after RT for HNC.

Methods: The TriNetX research network was queried for all cases of HNC treated with RT and stratified into cohorts of patients with and without xerostomia/Salivary disturbances. Demographic, comorbidity, and treatment factors were assessed. Statistical analyses were conducted within the TriNetX platform.

Results: Preliminary results demonstrated data from 11 included healthcare organizations, with 8610 HNC patients who received RT. Mean age was 67 (SD:13) years, with no significant differences between cohorts. 1892 patients with xerostomia were identified. A higher proportion of patients with xerostomia were male (76% vs. 69%, p-value < 0.0001) and white (79% vs. 71%, p < 0.0001). A lower proportion of xerostomia patients were black (11% vs. 16%, p < 0.0001).
Amongst xerostomia patients, a higher proportion were diagnosed with base of tongue (22% vs. 12%), other parts of tongue, (9% vs. 6%) and tonsillar (23% vs. 12%) cancers compared to those without xerostomia. However, a lower proportion were diagnosed with laryngeal (13% vs. 21%) and thyroid (3% vs.16%) malignancies (p < 0.0001).
The cohorts significantly differed when stratified by cancer histology. Xerostomia patients had a higher proportion of squamous cell neoplasms (88% vs. 73%, p< 0.0001), but lower proportion of adenomas and adenocarcinomas (8% vs. 20%, p< 0.0001), or epithelial neoplasms (3% vs. 5%, p=0.024).
A lower proportion of xerostomia patients had stage I disease (11% vs. 17%, p< 0.0001), whereas a higher proportion had stage IV disease (36% vs. 29%, p< 0.0001).

Conclusions: Patients with certain subsites of HNC, and those presenting at a high stage may be at increased risk of developing xerostomia after RT. Susceptible primary subsites should be considered for radiation sparing treatment.